The Welshman stepped down from the Craven Cottage hotseat three days ago after one season at the helm, turning down the offer of a new deal but claiming he had had no contact with any other club.
Joorabchian told BBC Radio 5 Live's Sportsweek programme: "As a manager he has ambitions to really compete at the top level and be the best he can. [Fulham] are where they are. They are a great top-10, mid-table club and I think Mark really wants to be right up there competing in the Champions League positions, up there competing for titles. He'd like to win some cups."
He added: "(The timing) was an unfortunate circumstance. The timing of the situation was such there were a couple of vacancies available.
"It had nothing to do with it whatsoever. You all realise Mark Hughes is a sincere man. He wouldn't do that.
"He sat down and thought about it and thought if he signs a two-year contract now and they go and buy players in the transfer market, but all the time looking over his shoulder thinking 'well if a bigger job comes along, a top-four club or maybe a place in Portugal, Spain, Germany, Italy that allows him to compete...' then he'd be sort of keen to move and that would be unfair to Fulham.
"He wanted to tell them and give them plenty of time. There was no better time to do so than at the end of the season.
"This has nothing to do with Aston Villa or Chelsea or any other club. Mark Hughes made decision to leave Fulham purely and simply because he didn't want to commit two years then look over his shoulder and disappoint them by leaving in the middle of his contract."
Asked about the possibility of the former Chelsea player returning to Stamford Bridge for a role in the dugout, Joorabchian replied: "There's a vacancy there but I'm sure they have their own planning. We have not spoken to them. They have not spoken to us.
"It's a club he has played fo so he knows the club well but it would be disrespectful of us to say 'yes, we'd like to go there' or here or whatever. It's a case of Mark sitting on the sidelines and seeing what opportunities there will be throughout Europe."